Vertebra cervicalis V (C5)
C5 is a typical mid-cervical vertebra with a robust body, well-developed articular processes, and transverse processes that provide attachment for muscles such as the longus colli and scalenus. Together with the other cervical vertebrae it supports the head and neck, allowing flexion, extension, lateral bending, and rotation. The neck functions as a balancing rod during locomotion. C5 is a frequent site of cervical vertebral stenotic myelopathy (CVM or “Wobblers”), in which developmental narrowing of the vertebral canal compresses the spinal cord, producing neurologic deficits (ataxia, weakness, spasticity) in young, rapidly growing horses, especially Thoroughbreds.
Origin: N/A (bone)
Insertion: N/A (bone)
Action: Support the head and neck; allow flexion, extension, lateral bending, and rotation; the neck acts as a balancing rod during locomotion
Cervical pathology causes neck stiffness and neurologic signs. Diagnosis involves radiography, ultrasound, myelography, or advanced imaging. Static or dynamic compression can be present.
## Overview Facet arthritis at the C5 level involves the articular process joints of the fifth cervical vertebra, a region frequently affected in clinical cervical osteoarthritis. Osteophytes here ca
Wobbler syndrome, also known as cervical vertebral stenotic myelopathy, is a neurologic condition caused by compression of the spinal cord in the neck. It leads to progressive incoordination (ataxia),
A young horse that shows progressive incoordination, especially in the hind limbs, or that appears “wobbly” needs veterinary neurologic evaluation. Neck stiffness or resistance to lateral bending can also indicate cervical issues.
## Overview Facet arthritis at the C5 level involves the articular process joints of the fifth cervical vertebra, a region frequently affected in clinical cervical osteoarthritis. Osteophytes here can produce neck pain, stiffness, and forelimb lameness via nerve-root irritation. It is one of the more common sites for therapeutic injection. ## Causes Repetitive biomechanical stress in athletic horses is the predominant cause. Conformational and traumatic factors contribute. ## Diagnosis Combination of clinical signs, imaging (radiographs and ultrasound), and response to diagnostic analgesia of the facet joint. ## Treatment Ultrasound-guided intra-articular corticosteroids can give temporary relief of neck pain and stiffness. Adjunctive anti-inflammatories and physical therapy complete the program. ## Recovery and Prognosis Relief after injection may be temporary. Progressive disease may require ongoing management. ## Prevention No proven specific prevention; maintain overall neck mobility and address early stiffness. Signs include: caudal neck stiffness; resistance to poll flexion or lateral bend; forelimb lameness unresponsive to distal blocks; radiographic changes at C5-C6
Wobbler syndrome, also known as cervical vertebral stenotic myelopathy, is a neurologic condition caused by compression of the spinal cord in the neck. It leads to progressive incoordination (ataxia), primarily in the hind limbs. There are two main forms: Type I (dynamic compression in young horses) and Type II (static compression in older horses due to osteoarthritis). ## What it is In Type I wobbler syndrome, developmental abnormalities of the cervical vertebrae cause narrowing of the vertebral canal and dynamic compression of the spinal cord during neck movement. It typically affects horses between 1 and 4 years of age, most commonly at C3 to C5. Type II wobbler involves static compression from osteoarthritic enlargement of the articular facets, usually affecting older horses at C5 to C7. Both forms result in damage to the spinal cord, leading to proprioceptive deficits and ataxia that is usually worse in the hind limbs. ## Signs and symptoms - Progressive hindlimb incoordination and ataxia - Wide-based stance and stumbling, especially when turning or going downhill - Toe dragging and difficulty backing - Neck stiffness or pain in some cases - In severe cases, weakness or falling - Symmetric or slightly asymmetric ataxia that is worse in the hind limbs than forelimbs - Positive cervical flexion test in many cases ## Causes and risk factors Type I wobbler is developmental and linked to rapid growth, genetic factors, and nutritional imbalances (especially copper deficiency or excess protein/calcium in young horses). Type II is associated with chronic wear and osteoarthritis of the cervical facet joints. Risk factors include large body size, rapid growth rates in young horses, and conformational issues that place abnormal stress on the neck. ## How it is diagnosed Diagnosis is based on clinical neurologic examination and confirmed with radiographs and myelography or MRI. Standing or recumbent radiographs can show vertebral canal narrowing or facet joint changes. Myelography or MRI provides the most accurate assessment of spinal cord compression. A neurologic grading system helps quantify the severity of ataxia. ## Treatment and management Treatment depends on the type, severity, and age of the horse. Conservative management includes stall rest, anti-inflammatory medication, and controlled exercise. For young horses with Type I, dietary management and restricted growth may help. Surgical options (ventral interbody fusion or dorsal laminectomy) are available for selected cases and can improve neurologic function in many horses. Prognosis varies widely depending on the severity and duration of compression before treatment. ## When to call the vet Contact your veterinarian promptly if your horse shows incoordination, stumbling, or difficulty backing or turning. Early diagnosis improves the chance of successful management or surgical intervention. ## Prevention For Type I wobbler in young horses, prevention focuses on balanced nutrition (avoiding excessive protein and calcium while ensuring adequate copper and other minerals) and avoiding overly rapid growth rates. Regular monitoring of at-risk young horses can help with early detection. ## Frequently asked questions **Can a horse with wobbler syndrome be ridden?** Many horses with mild to moderate signs can be ridden carefully after treatment, but those with severe ataxia are usually retired for safety reasons. **Is surgery always successful for wobbler syndrome?** Surgical success rates are good in appropriately selected cases, but results vary depending on the severity and chronicity of spinal cord damage. **Is wobbler syndrome hereditary?** There is a genetic component, especially in Type I. Breeding horses with wobbler syndrome or from lines with high incidence is generally discouraged. This information is for educational purposes only. Always consult with a licensed veterinarian for diagnosis and treatment of your horse. Signs include: Progressive hindlimb incoordination and ataxia; wide-based stance and stumbling, especially when turning or going downhill; toe dragging and difficulty backing; neck stiffness or pain in some cases; in severe cases, weakness or falling; symmetric or slightly asymmetric ataxia worse in hind limbs; positive cervical flexion test in many cases
Cervical pathology causes neck stiffness and neurologic signs. Diagnosis involves radiography, ultrasound, myelography, or advanced imaging. Static or dynamic compression can be present.
A young horse that shows progressive incoordination, especially in the hind limbs, or that appears “wobbly” needs veterinary neurologic evaluation. Neck stiffness or resistance to lateral bending can also indicate cervical issues.
See the Fifth Cervical Vertebra (C5) on our interactive 3D horse model. Open 3D Model